Many automobiles have the capability to communicate with a cellular phone. For example, a cellular-phone may have Bluetooth capabilities that allow mating between the cellular-phone and the automobile so that the user of cellular phone can communicate through the automobile subsystems, e.g., use an in-vehicle microphone and/or speaker.
In addition, it is conventional to use a key to enter and drive the automobile. The key is for security, e.g., to prevent theft. However, keys can be lost. High security keys are often difficult to duplicate especially for the higher security keys. Keys are one more thing that a person needs to carry.